Smokeless explosive.



UNITED STATES PigTENT OFFICE.

MODESTO ABELLI, OF TURIN, ITALY, ASSIGNOR TO DINAMITE NOBEL SOOIETE ANONYME.

I sMoKELEss EXPLOSIVE. v

No. 899,855, Specification of Letters Patent. Patented Sept. 29, 1908.

Application filed. November 1, 1905. Serial l lo. 285,461.

To all whom it may concern:

Be it known that I, Monnsro ABELLI, a sub ect of the King of Italy, and a resident of Aviglianaf Turin, Italy, have invented certain new and useful Im rovements in Smokeless Explosives, of which the following is a specification.

This invention relates to smokeless pow- .ders and explosives, for use either in guns for war or sporting purposes, or for use in blast-'- ing; but more especially for use in guns or fire-arms.

For a long time makers'of smokeless powder, especially for war purposes and hunting uses have sought to obtain a product which shall develop the. lowest temperature when exploded that is consistent with the maintenance of the greatest ballistic force, in order to reduce to a minimum the erosive effects on the metal of the combustion chamber and bore of the gun.

Several substances have been recognized as correctives, especially in powders which contain nitroglycerin, but up to the present, so far as known, none ofthese has given results which are really satisfactory, as the greater part of such substances have the efiect of diminishing the ballistic force or energy of the powder. In studying this prob lem I have found nitroguanidin, an amido derivative of carbonic acid, which has the formula 'NH,.C(NH)NHNO,, and .which in certain circumstances, is itself capable of explosion, but which has a very low temperature of explosion. This derivative may be suitably and usefully applied in the manue facture of explosives, and particularly of powder for military and sporting uses, with the important advantage that it diminishes in a marked degree the corrosive eifect on the metal of the gun. This substance-nitroguanidin-is eminently stable, unalterable by moderate heat (being decomposed only ,by a temperature above 200 0.), insensible toshocks and friction, and which contains already, aside from a large quantity of nitrogenwfrom 45 to 50 per cent), nearly the wholef'of the oxygen necessary to transform it into gas,--is introduced in suitable proportion into the composition of explosives having a base of nitro-cellulose, with or-withoutfiinitroglycerin. The nitrocellulose may be substituted wholly or in part by nitrohydrocellulose, nitrated wood, straw, jute,.o r other substance of a similar kind. Also, the nitroglycerin may be substituted, wholly or in part, by nitrobenzol, nitrotoluol, and other similar compounds, act ng the part of fixed solvents, as the nitroglycerin.

Among the different formulae which res ond'best in giving to projectiles remarkably pressures, and above all with temperatures of explosion so moderate that the corrosion of the ,metal of the gun is almost wholly, eliminated, the following may be given Nitroglycerin, 45 parts by weight. Nitrocellulose, 30 Nitroguanidin, 25 Excellent results may be obtained also with the following com ositiont- In 100 parts by weig t:

The nitroguanidin is only sli htly soluble in cold water, and presents itself in the form of a very fine crystallized powder, and its mixture with the pul ed nitrocellulose may be effected'in a satis actory, way by any of the known processes employed in the powder factories or mills for makin 'smokeless powder; that is to say, either dry or in suspension in water; also with a volatile solvent or without a solvent. The mixture thus obtained may be very easily gelatinized, with or without the addition. of nitroglycerin; or with any of the solvents of nitrocellulose, as acetone, ether, acetic ether, amyl acetate, etc. or likewise without solvents, by means of rolling hot or cold.

The paste obtained with one of the processes above indicated responds toall the exicapable of being transformed by any one of the systems usually employed (rolling or compression) into strips, leaves, cylindrical threads, bars, cords, tubes or-grains of any suitable form or size.

The nitroguanidin -may enter with success gencies of manufacture of a good powder,

high initial velocities with relatively low position ofall explosiveshaving as a base,

into the composition of all explosives having a nitroglycerin base, as Well as into the comoxidizing salts. 7 1$ I have ascertained that we may obtain very powerful explosives, though of great I insensibility to shocks and friction, bycoupthose of" certain explosives already known; 10

ling the properties of nitroguanidin,' with and Well characterized, which are capable of disen aging in their combustion a great number 0 calories. guanidin may be mixed with picric -acid,

either when this latter is in estate of fusion (to be more precise, during the act of this fusion) or by a simple mixture of the two substances in a crystalline state, or pulverized,'or crystallizing them together from their solution 1n a common solvent.

The mixture maybe suitably compressed, either alone or after the addition of yariable quantities of ox genating salts .(as nitrates, ehlorates, perchlbrates, chromates, permanganates, etc). For picric acid we may suborgy and possessing also great insensibilitystitute its salts, orsubstances ap ertaming to the dliferent categories of mtro erivatives of the aromatic series. These formulae may 1 have also found th'at the znidition to explosives used for mining purposes, of metallic powders such I as "iron, n'aluminum; silicon, iGIIO-SllICOIl, magnesium; zinc, and alloys] thereof, will produce explosives of great ento shocks and friction. This is due 'to the high temperature arising'from the oxidation of said metals. As examples ofsuch mix- Thus for example the nitrotunes f or compeunds' the following formula) All the preceding mixtures, either in powder, or granules, after having been more or lessstrongly compressed, by reason of their stability and their insensibility toshoclrs and friction, can be usefully'employed for charging hollow projectiles, offering in comparison with the explosives now-in use a greater security in firing and in the facility with whichthey may be preserved. To prevent .the action of humidity on mixtures prepared with oxygenating salts, We may add a small quantity (say about 5 er cent of the mass of powder) of'iatt or oi'y matter, either vegetable or miliera or lieu thereof a resinous substance, asvarnlsh, lac uer, colophony, or

any othersubstance capa is of producing a similar effect;

Having thus described ,my invention, I 'claim' A smokeless owder composed of nitrog ce'rin,nitroce ulose, and nitrogu'anidin, in en stantially the pro ortions specified. In witness whereof I have hereunto signed my namethis 12th day of October 1905, in the presence of two subscribing witnesses. MODESTO ABELLI. Witnesses:

Go'rraano O. Pmom, SEGONDO YORTA. 

